@mainbasket: most probably you have created the post before, and saved as draft, so the publish date is set to the date on which you first created the draft. And now when you have published it is published with the same old date as the draft and it has gone down the newer dated posts. To solve this change the publish date of each post.

But i can see one post on 17th and one on 18th at this time i am typing in.